English: Islamic decoration makes great use of geometric shapes which have developed over the centuries. They are usually distinguished from the arabesque, the term for decoration in Islamic art based on curving and branching vegetal forms. But sometimes foliage and linear geometric patterns are combined in a single design, and some purely abstract linear patterns adopt designs that seem clearly derived from vegetal arabesque ones. The floral designs have evolved into beautiful and highly complex patterns, still used in many modern day settings. The square and rectangle play a significant role in Islamic geography. Some of the reason for this is façades built from circular and triangular bricks. This ornamental brickwork casts shadows in the strong desert sunlight and creates a three-dimensional effect. A recurring motif is a small central square turned 45 degrees within a larger square. Another source for the square motif is woven baskets [Wikipedia.org]